The background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
Safety has been an important concern when using utility knives as many users inadvertently cut themselves with the exposed blades. Some efforts have been made to address this safety concern.
For example, U.S. Pat. No. 8,347,509 teaches a blade cartridge with a blade cover that defaults to a closed position in which the blade cover surrounds the otherwise exposed portion of a blade. A spring is used to push the blade cover into the closed position, and the blade cover remains in the closed position until pressure is applied to push the cover to an open configuration where the blade is exposed for use.
This and all other publications referenced herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
Unfortunately, the '509 Patent's blade cartridge and blade cover fails to address several other safety issues, for example, injuries that can occur from an inadvertent detaching of the cartridge or blade from a tool handle.
U.S. Pat. Nos. 7,475,480 and 8,099,868 each strive to solve this problem by featuring a flexing latch to secure the handle to the cartridge. While the cartridge is inserted into the handle, the latches flex into a strained position in order to fit into the receiving channel of the handle. Once the cartridge has been fully inserted into the handle, the latches then return to a relaxed, unstrained position by pushing through openings on either side of the handle. Such a latching mechanism is useful in securing the blade.
Unfortunately, the cartridge is at risk of inadvertent detachment from the handle because the latches are positioned on the handle at a place where users commonly squeeze their thumb and first finger together to grip and manipulate the tool.
Thus, there is still a need for improved and safer utility knives and utility knife components.